1. Field of the Invention
The invention relates to display control circuits for Vacuum Fluorescent Display (VFD).
2. Description of the Related Art
The fast-growing high-tech industry has incorporated display monitors in more and more electronic devices; making life easier and more convenient for humans.
Liquid Crystal Displays (LCDs) are very common in high-tech devices, such as cellular phones, televisions, computer display monitors, and other devices. Compared with Cathode Ray Tubes (CRTs), LCDs have smaller sizes and are easier to be assembled in electronic devices. However, LCDs comprise backlight modules resulting in relatively diminished images when bright light surrounds the outside of the display, such as sunlight.
Compared with LCDs, Vacuum Fluorescent Displays (VFDs) provide high brightness. Meanwhile, since VFDs can provide clear images despite being surrounded by sunlight and the cost of VFDs is cheaper than LCDs, VFDs are a suitable display option for some electronic devices.
VFDs are generally utilized in audio devices, microwave ovens or clocks to display numerals, English letters, or simple patterns. The VFD comprises a screen. The screen can be divided into a plurality of display units. To control the brightness and image displayed in the display units, each display unit requires a clock signal and an image signal.
Because the display units of the conventional VFD each requires a exclusive clock signal to control the brightness, the conventional display control circuit of the VFD comprises a plurality of clock signal generators generating the clock signals for different display units. The clock signal generators occupy large circuit area and increase production costs. It is desirable to develop a smaller-sized and cheaper display control circuit to be utilized in VFDs.